+/*
+ * Test to determine whether the hugepage is "active/in-use" (i.e. being linked
+ * to hstate->hugepage_activelist.)
+ *
+ * This function can be called for tail pages, but never returns true for them.
+ */
+bool page_huge_active(struct page *page)
+{
+ VM_BUG_ON_PAGE(!PageHuge(page), page);
+ return PageHead(page) && PagePrivate(&page[1]);
+}
+
+/* never called for tail page */
+static void set_page_huge_active(struct page *page)
+{
+ VM_BUG_ON_PAGE(!PageHeadHuge(page), page);
+ SetPagePrivate(&page[1]);
+}
+
+static void clear_page_huge_active(struct page *page)
+{
+ VM_BUG_ON_PAGE(!PageHeadHuge(page), page);
+ ClearPagePrivate(&page[1]);
+}
+